Brew coffee and prep the chocolate sauce. Set aside.
Fill a large mug ¾ of the way with coffee. Add chocolate sauce and peppermint. Stir.
Steam or heat the plant-based milk on the stove. If desired, froth with a hand or automatic frother. If you don't have either, you can also froth it in your blender or (carefully) shake it up in a sealed jar.
Combine the coffee mixture with the milk and give it a final stir.